Peel nectarines; cut into halves and remove pits.
Treat to prevent darkening .
Rinse and drain.
Cook a few nectarines at a time in water until heated through.
Drain and pack into hot jars, leaving 1/2-inch head space.
Heat nectar and nutmeg just to boiling.
Pour over nectarines, leaving 1/2-inch head space.
Remove air bubbles.
Process 25 minutes in boiling water bath.